In last week's lesson, I explained why you shouldn't save your opinion for a 'surprise conclusion'. Look at the following introduction and conclusion for an essay about whether it is better for students to work alone or in a group:
People have different views about the most effective way for students to work. While there are some advantages to studying alone, I personally believe that group work is usually more productive.
In conclusion, both individual and group study can be useful under different circumstances, but I generally prefer to work with others as part of a team.
Notice that my 'position' is clear in the introduction, so the conclusion simply repeats my view in a different way.